1. Field of the Invention
The present invention relates to a connecting structure for connecting to an electro-osmotic flow pump using an electro-osmotic phenomenon, a flow path control section including the connecting structure, a fuel cell-type power generation device including the flow path control section, and an electronic apparatus including the fuel cell-type power generation device.
2. Description of Related Art
Recently, fuel cells have attracted attention as a clean power source having a high energy conversion efficiency and have been widely used for a fuel cell automobile, a mobile device, and an electric home. A fuel cell is classified into two types of the reforming one and the direct one. The reforming-type fuel cell is based on a method to generate hydrogen out of fuel and water by using a reformer and to subsequently supply hydrogen to a power generation cell (fuel cell body). The direct-type fuel cell is based on a method to supply fuel and water to a power generation cell without reforming fuel and water. In any of these methods, a pump is used as a power source for sending fuel and water. Pumps include the mechanical ones such as the centrifugation-type one, the capacity rotation-type one, and the capacity reciprocation one. Many patent applications relating to a pump using a piezoelectric actuator in particular have been filed in the field of mobile devices requiring a small size. However, a mechanically operating pump using a piezoelectric actuator or the like has a problem in the life of the moving part thereof. Thus, such an electro-osmotic flow pump that sends liquid without having a mechanical moving part has been suggested.
An electro-osmotic flow pump uses the electro-osmotic phenomenon and has a structure as shown in FIG. 24. As shown in FIG. 24, the electro-osmotic flow pump comprises an electro-osmotic material 502 filled in a tube member 504; an electrode 501 provided at the upstream side of the electro-osmotic material 502; and an electrode 503 provided at the downstream side. The electro-osmotic material 502 is made of, for example, dielectric material, such as, silica fiber, provided in a direction of the flow of the tube member 504.
The electro-osmotic flow pump operates based on the principle as described below. Specifically, when the dielectric material of the electro-osmotic material 502 is in contact with liquid, the surface of the dielectric material is charged and counter ions in the liquid are collected at the neighborhood of the contact interface to cause excessive charge. When a voltage is applied between the electrode 501 and the electrode 503 to cause an electric field in the electro-osmotic material 502, counter ions in the liquid move and the liquid entirely flows due to the viscosity of the liquid. When the electro-osmotic material 502 is silica, the surface of silica becomes Si—O− and the surface of silica is negatively charged to collect positive ions (counter ions) in the liquid and to cause excessive positive charge in the liquid. Thus, the fluid flows in the direction as shown in FIG. 24 by applying a voltage so that the potential of the electrode 501 is higher than the potential of the electrode 503.
The electro-osmotic flow pump is advantageous in that no moving part is used, the structure is simple, the size can be reduced, and neither pulsation nor noise is caused and the like. However, it is required to sufficiently permeate liquid in the electro-osmotic material during the operation of the pump. In a conventional connecting structure of an electro-osmotic flow pump, it is difficult to sufficiently permeate the liquid in the electro-osmotic material. Therefore, the phenomenon that the liquid was not sufficiently sent was caused.
In view of them, the present invention has been made in order to solve the above-described problem. It is an object of the present invention to sufficiently permeate liquid in electro-osmotic material during the operation of an electro-osmotic flow pump.